1216100609 has 2 divisors, whose sum is σ = 1216100610. Its totient is φ = 1216100608.

The previous prime is 1216100603. The next prime is 1216100647. The reversal of 1216100609 is 9060016121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1009459984 + 206640625 = 31772^2 + 14375^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1216100609 is a prime.

It is not a weakly prime, because it can be changed into another prime (1216100603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 608050304 + 608050305.

It is an arithmetic number, because the mean of its divisors is an integer number (608050305).

Almost surely, 2^1216100609 is an apocalyptic number.

It is an amenable number.

1216100609 is a deficient number, since it is larger than the sum of its proper divisors (1).

1216100609 is an equidigital number, since it uses as much as digits as its factorization.

1216100609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 26.

The square root of 1216100609 is about 34872.6340989607. The cubic root of 1216100609 is about 1067.3900956530.

The spelling of 1216100609 in words is "one billion, two hundred sixteen million, one hundred thousand, six hundred nine".